Karnataka's regional party lawmaker and popular farmer leader K.S. Puttannaiah has passed away. He was 69, an official said on Monday.

Puttannaiah died on Sunday night at Mandya, about 100km from here.

"Puttannaiah breathed his last at 10.55 p.m. on Sunday night in a state-run hospital at Mandya after a cardiac arrest," the district official told IANS.

Puttannaiah was a lawmaker of the Sarvodaya Karnataka Party (SKP) from the Melkote Assembly segment in the old Mysuru region since May 2013.

"Puttannaiah was rushed to the hospital last evening after he complained of chest pain while watching a kabaddi game at a stadium in the town," the official said.

The regional outfit (SKP), merged in March last year with Swaraj India, floated by former Aam Aadmi Party rebel leader Yogendra Yadav in New Delhi.

Puttannaiah's death came two days after the Supreme Court on Friday delivered the final verdict in favour of Karnataka in the inter-state Cauvery river water sharing dispute with neighbouring Tamil Nadu.

Puttannaiah was the sole farmers' leader in the state Assembly after getting elected for the first time from the Pandavapura segment in the same district in the 1994 election though he lost in the 1999, 2004 and 2008 elections.

Chief Minister Siddaramaiah and leaders of other political parties and farmers' associations mourned Puttanaiah's sudden demise.

"Puttannaiah's death had come as a shock. The state's farmers' movement has lost a prominent leader," said Siddaramaiah in a statement here, adding that he was saddened by the loss of his friend.

In a tweet, Congress state unit President G. Parameshwara said: "Puttannaiah was a proud farmer, activist and an outstanding leader. He contributed a lot to the state's agriculture growth. He was an affable person. Saddened by his sudden demise. Condolences to his family."

Saying Puttannaiah was a charismatic leader, Yogendra Yadav tweeted that "the farmers movements all over the country would miss this rare bridge between farmers' struggles of the previous and current generation".